This invention relates generally to rib-type and standing seam-type metal roofs and relates more particularly to means for mounting metal roof panels in spaced relationship above an existing roof structure.
In a metal roof structure commonly referred to as a "rib" type, the edges of adjacent panels are placed in overlapping relationship, and the overlapped panels are secured to the structural members (purlins) underlying the panels by appropriate securing means, such as self-tapping sheet metal screws or clips. Commonly, each panel of a rib-type metal roof is elongate in form and has a plurality of parallel upstanding ribs formed therein which run lengthwise of the panel. In standing seam-type metal roof structures, raised edges of adjacent panels are placed against one another and bent downwardly to provide the standing seam. The panels of both types of roof structures, being metal, are known to experience dimensional changes, i.e., expansion and contraction, due to temperature variations to which the panels are exposed. In order to alleviate stresses and strains spawned by the expansion and contraction of the panels, devices or clips may be interposed between the panels of the roof and the underlying structural members for accommodating longitudinal dimensional changes in the panels. One such device for rib-type roofs is shown and described in U.S. Pat. No. 4,429,508, and one such device for standing seam-type roofs is described in U.S. Pat. No. 4,575,983.
It is an object of the present invention to provide an improved device for mounting roof structures over existing roof structures.
Another object of the present invention is to provide such a device which is uncomplicated in construction and effective in operation.
Still another object of the present invention is to provide such a device which is well-suited for supporting a standing seam type roofing panel above an existing rib-type roof.
Yet another object of the present invention is to provide means for supporting a rib-type roofing panel above an existing standing rib-type roof.
Another object of the present invention is to provide such a device which is well-suited for supporting a standing seam-type roofing panel above an existing standing seam-type roof.
A further object of the present invention is to provide a roofing system which incorporates such a device.